Humans are born with a propensity to look at faces, yet face recognition undergoes a surprisingly prolonged development into the late teens. Likewise, neuroimaging studies discovered prolonged development of face- selective regions in ventral temporal cortex (VTC) during childhood and into the teens involving age-related increases in face selectivity. Understanding the neural substrates of the development of face recognition is important because of the significance of face procesing in children's visual, social and emotional development, and is a prerequisite for understanding clinical conditions involving atypical face processing. However, it remains unknown how face selectivity develops, or how neural developments in VTC lead to better face recognition. We propose to elucidate the functional and structural brain mechanisms that underlie the development of face recognition abilities, using cutting-edge neuroimaging and behavioral methods acquiring multimodal data in the same subjects, cross-sectionally and longitudinally. In Aim 1 we will determine the factors that drive the development of face selectivity in VTC and examine the relationship between structural and functional developments. Thus, we will acquire behavioral, anatomical and functional data in each subject comparing data across young children (5-7 year olds, yo), children (9-11yo), and adults (23-25 yo) cross- sectionally and follow these developments longitudinally to determine: (1) what is the role of recent and cumulative experience in shaping face selectivity, (2) if viewing faces with central vision drives the development of face selectiviy, (3) if development of white matter structures is linked to development of face selectivity in VTC and (4) what is the reliability, sequence and longitudinal trajectory of the development of face selectivity, eccentricity bias and white matter structures in VTC. Longitudinal measurements wil provide unprecedented spatial and temporal precision revealing the casade of developments asociated with the emergence of cortical selectivity. In Aim 2 we will determine how neural developments lead to better face recognition. Proficient face recognition requires fine discrimination among similar faces and identification of specific faces across their many possible appearances. However, the neural mechanisms that underlie the development of these two key processes are unknown. Thus, using cross-sectional measurements of performance and brain responses in children (7-11 yo), adolescents (12-16 yo) and adults (24-28 yo) we will determine (1) if developmental changes in neural tuning to face identity and view lead to beter face discrimination and (2) if developmental increases in specialization to faces in VTC lead to beter face identification. We expect these studies to significantly advance our knowledge of the neural mechanisms that underlie the development of cortical selectivity to faces and improvements in face recognition, as well as progress our understanding of the neural mechanisms of long-term cortical plasticity.